This project will allow us to characterize the behaviour of RyR in relation with mitochondrial function in human skeletal muscle during HF and identify beneficial effects of exercise training routinely proposed to HF patients. The analysis of circulating factors will allow us to establish a relation of cause and effect between myocardial dysfunction and muscle dysfunction. This project could thus open important perspectives in therapeutic. Compounds analogues to JTV-519, acting in stabilizing RyR channels, could be prescribed as a potent medication for HF. This project could thus be determinant in the comprehension of the regulation of Ca2+ and energetic metabolism in human skeletal muscle which could be an appropriate model to evaluate the effects of new pharmacological agents.